fn 2 rn 0 read error I/O error on NT

[manoj24]

I am trying to recover files from DLT4000 tape sent to me by my company but can't run scanner command.
It gives the following error:
fn 2 rn 0 read error I/O error
Looks to me Blocksize issue
How do i change the block size in NT machine. I know Registry setting has to be changed but can anybody give me the exact command or procedure how to do it.

Thanks

 

[WhiteWiz]

environment variable not a registry setting

set NSR_DEV_BLOCK_SIZE_DLT7000=64

from what i understand the default for scsi is 64 and fibre channel is 128

i have the same problem but changing my block size hasn't seemd to work. Where can i find more info on this? Let me know if it isn't the block size.

 

[owieck]

I ran into a similar problem (same error message) trying to recover a tape from a (Linux) Legato backup server at another location. It turns out I didn't need to set the environment variable. I loaded a different device driver for my SCSI controller--it's a Compaq and I was using the Microsoft Drivers. (Should have known better.) Anyway, the max block size was set to 64k in the MS drivers. The Compaq drivers gave it a more generous allowance. The tape(s) I was trying to read are written at a larger block size (512k I think) thus the problem.

It appears that most "decent" drivers will provide a registry key to set the max block size. It's mentioned in another post on this site (see link below). Your registry key will vary depending on vendor. Good luck and hope this helps!

http://www.tek-tips.com/gviewthread.cfm/lev2/7/lev3/49/pid/480/qid/377342

P.S.: Legato also helpfully provides a Unix-style "mt" command from which you can see (and also set, I think) parameters on your actual device--including the device block size. It has the form

mt -f tape_device_name command

I would guess you can look up the options in their command line reference manual or with a quick net search.